Seals, especially seals that are subject to dynamic loads, experience wear over their predicted lifecycle in the form of a variety of wear phenomena. The seal contact stress is reduced due to material fatigue and the contact pressure force also declines. The dimensions of the seal change as a result of wear and setting behavior. These processes lead to leaks in the first instance and ultimately cause the seal system to fail.
The possibility of incorporating a leak monitoring device in the seal to monitor leaks from seals is already known in the art. DE 10 2007 007 405 B4 discloses an electrical device for detecting the state of wear of a dynamic seal element. The seal element comprises an electrically conductive section and an electrically non-conductive section, which is in contact with the machine component to be sealed. The machine component is also electrically conductive. The electrically non-conductive sealing material becomes worn due to wear on the seal element, causing the electrically conductive sealing material to come into contact with the machine component. This closes an electric circuit, making it clear that the seal element is worn. The disadvantage of this embodiment is that it is not possible to detect gradual changes in the seal condition. It is only possible to establish that the limit of wear has been reached and that the seal element must be replaced.